Nanoconfined Expansion Behavior of Hollow MnS@Carbon Anode with Extended Lithiation Cyclic Stability

The construction of hollow nanostructure by compositing with carbonaceous materials is generally considered an effective strategy to mitigate the drastic volume expansion of transition metal sulfides (TMSs) with high theoretical specific capacity in the process of lithium storage. However, designing well-controlled architectures with extended lithiation cyclic stability, and ease the expansion of the electroactive materials into the reserved hollow spaces still needs to be developed. Herein, using MnS as an example, the hollow double-shell carbon-coated TMSs architecture is designed to achieve the controllable operation of shell thickness to regulate interfacial stress. The functional architecture enables the high-capacity MnS to reach reversible capacities and extended lithiation cycling stability at high current densities. In situ transmission electron microscopy, optical observation characterizations and finite elements are used to analyze the nanoconfined expansion behavior of hollow MnS@C anodes. The as-designed hollow structure with a carbon shell thickness approximate to 12.5 nm can effectively restrict the drastic expansion of MnS nanoshell into inner voids with compressive stress. This study demonstrates a general strategy to design functional carbon coating metal sulfides with tailored interfacial stress.

Automated summary

The construction of hollow nanostructure by compositing with carbonaceous materials is an effective strategy to mitigate the volume expansion of transition metal sulfides (TMSs) during lithium storage. However, designing well-controlled architectures to achieve extended cyclic stability and ease expansion of the electroactive materials into the reserved hollow spaces is still a challenge.